1. FIELD OF THE INVENTION
This invention is directed to new organic compounds and is particularly concerned with novel 6-phenyl-4H-s-triazolo-[4,3-a][1,4]benzodiazepines and a process for the production thereof.
The novel compounds and the process of production therefor can be illustratively represented as follows: ##SPC3##
Wherein R is selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, inclusive, phenyl, benzyl and -COOR' in which R' is alkyl of 1 to 4 carbon atoms, inclusive; wherein R.sub.1 is selected from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, inclusive; and wherein R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, inclusive, halogen, nitro, cyano, trifluoromethyl, and alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkanoylamino and dialkylamino in which the carbon chain moieties are of 1 to 3 carbon atoms, inclusive.
The process of this invention comprises: condensing a 1,3-dihydro-5-phenyl-2H-1,4-benzodiazepine-2-thione of formula I in an organic solvent, e.g., a lower-alkanol of 1 to 4 carbon atoms, inclusive, or cyclohexanol with an acid hydrazide II, at a temperature between 60.degree. and 120.degree. C. to give a mixture containing the corresponding 2-(2-acylhydrazino)-5-phenyl-3H-1,4-benzodiazepine of formula III and the corresponding 6-phenyl-4H-s-triazolo-[4,3-a][1,4]benzodiazepine (IV). Under vigorous conditions IV is obtainable predominately. The partially condensed compound of formula III can be separated from IV by conventional methods such as extraction, chromatography, crystallization and the like, and can be converted to the corresponding triazolo-[4,3-a][1,4]benzodiazepine (IV) by heating it up to and above the melting point. Alternatively, the first obtained mixture of III and IV may be heated above the melting point to convert the partially condensed compound (III) to compound (IV).